1. Field of the Invention
The present invention relates to an ion detector which detects positive ions and also to an ion detector which detects positive ions and negative ions.
2. Related Background Art
Conventional ion detectors including conversion dynodes that emit secondary electrons by ion collisions, scintillators that emit light upon incidence of the secondary electrons emitted from the conversion dynodes, photodetectors that detect the light emitted by the scintillators have been known (refer to, for example, Japanese Patent Application Laid-Open No. H10-188878, Japanese Patent Application Laid-Open No. S63-276862 and Japanese Patent No. 4639379).